Content publishers have space (e.g., on the publisher's web page) that they sell to advertisers or other content providers directly or through intermediaries, such as brokers. After fulfilling committed purchases, a publisher often has excess space inventory (called “remnant inventory”) that the publisher attempts to sell through a remnant inventory marketplace. This remnant ad inventory market is a “spot” or “auction” type of market.
When a publisher participates in several networks for selling space, and one or more of those networks transact inventory with other networks, the process of matching a seller with a buyer may involve having a publisher sequentially pass available space to several networks one at a time, who in turn, sequentially pass that available space to their customers one at a time until a buyer is found. Thus, a request may pass through a long chain of offers/bids from multiple entities before being matched with a buyer. This daisy chain of interactions can slow down the process of selecting advertisements or other content for delivery to a consumer.